Adherent bacterial populations on the bovine rumen wall: distribution patterns of adherent bacteria

Fourteen tissue sites from the bovine reticulo-rumen were examined by scanning electron microscopy to determine the distribution patterns of bacterial populations adhering to the epithelium. Although diet variations did not appear to influence the total number of tissue-adherent bacteria present in adult Herefords, diet affected their distribution. It appeared that the distribution of the bacterial populations may be directly affected by the physical state of the digesta. The digesta may be mechanically removing adherent bacteria from the tissue surface by abrasive action. The total adherent population consisted of subpopulations with separate distribution patterns, and macropopulations of morphologically similar bacteria were occasionally observed at specific sites on the epithelial surface. Ureolytic organisms on the epithelium followed a distribution pattern considerably different from the general bacterial distribution.